LONDON — With a surge of medals in track and field, the United States has sprinted ahead of China and is poised to finish No. 1 in the medals table at the London Olympics.

Heading into the final weekend of competition, the U.S. tops both the gold and overall medals races after trailing the Chinese for most of the games. It could be the most golds ever collected by the Americans on foreign soil.

Midway through Friday's events, the Americans led China in total medals, 90 to 81, and golds, 39 to 37.

Bill Mallon, a veteran American medals prognosticator, projects the U.S. could pick up 15 more medals, including six golds, before the games close Sunday night.